Up to now, as a molding resin composition for a sliding part, there is known a composition obtained by adding several fillers to a polytetrafluoroethylene (PTFE) powder. For example, JP-B-36081/1974 and JP-A-72770/1983 disclose a resin composition having an improved sliding characteristic obtained by mixing a PTFE powder with a metal powder and a carbon graphite or a carbon fiber. However, since PTFE can not be subjected to melt-process such as an ordinary injection molding, the PTFE must be processed by a compression molding method having a low process productivity. Further, in a composition for the compression molding, aspect ratio of a fibrous material which is mixed should be small in view of pressure transferability. Consequently, the obtained molded article is not fully improved in mechanical strength.
Also, there are known injection moldable resin compositions obtained by adding various fillers (for example, a carbon fiber and molybdenum disulfide) to a melt-processable fluorine-containing resin such as tetrafluoroethylene-ethylene copolymer (for example, PLASTIC, Vol. 42, No. 7, pages 51 to 53). However, these compositions do not fully satisfy requirements that the sliding characteristic at a high temperature, particularly abrasion coefficient should be made lower and fluctuation range of friction resistance should be made smaller. Also, the compositions have insufficient abrasion resistance to a soft metal such as aluminium.
An object of the present invention is to provide a melt-processable resin composition for producing a fluorine-containing resin molded article which is improved in the sliding characteristic at a high temperature and the abrasion resistance to a soft matal while maintaining mechanical strengths.